﻿using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class GameStart : MonoBehaviour
{

    public Button _BtnCapture;
    public RectTransform _CapTransform;

    void Start()
    {
        Screen.SetResolution(1024, 1024, false);
        _BtnCapture.onClick.AddListener(Capture);
    }

    private void Capture()
    {
        Rect rect = _CapTransform.rect;
        rect.position = Vector2.zero;
        CaptureScreenshot2(rect);
    }

    Texture2D CaptureScreenshot2(Rect rect)
    {
        Camera camera = Camera.main;
        // 创建一个RenderTexture对象  
        RenderTexture rt = new RenderTexture(Screen.width, Screen.height, 0);
        // 临时设置相关相机的targetTexture为rt, 并手动渲染相关相机  
        camera.targetTexture = rt;
        camera.Render();
        //ps: --- 如果这样加上第二个相机，可以实现只截图某几个指定的相机一起看到的图像。  
        //ps: camera2.targetTexture = rt;  
        //ps: camera2.Render();  
        //ps: -------------------------------------------------------------------  

        // 激活这个rt, 并从中中读取像素。  
        RenderTexture.active = rt;
        Texture2D screenShot = new Texture2D((int)rect.width, (int)rect.height, TextureFormat.RGB24, false);
        screenShot.ReadPixels(rect, 0, 0);// 注：这个时候，它是从RenderTexture.active中读取像素  
        screenShot.Apply();

        // 重置相关参数，以使用camera继续在屏幕上显示  
        camera.targetTexture = null;
        //ps: camera2.targetTexture = null;  
        RenderTexture.active = null; // JC: added to avoid errors  
        GameObject.Destroy(rt);
        // 最后将这些纹理数据，成一个png图片文件  
        byte[] bytes = screenShot.EncodeToPNG();
        string filename = Application.dataPath + "/Screenshot.png";
        System.IO.File.WriteAllBytes(filename, bytes);
        Debug.Log(string.Format("截屏了一张照片: {0}", filename));
        return screenShot;
    }
}
